I guess I learned my maths a long time ago when mathematicians used chalk and pencils…
I stumbled upon web stats for the e-mail system of a French mathematical laboratory. They get hits from all over the world but most are from France. Interestingly the number 1 UserAgent is X11/Linux. In the top 15 UserAgents there are 4 representing 19.85% share. That other OS is there of course and also MacOS but GNU/Linux is tops.
See Web-mail Stats for CNRS.fr.
Interesting, eh? Do these guys buy retail? Pick from a menu provided by their organization? Install their own OS? They even have remote GNU/Linux sessions over SSH. Cool.